edu.illinois.cs.cogcomp.core.io

Class LineIO

java.lang.Object

edu.illinois.cs.cogcomp.core.io.LineIO

public class LineIO
extends Object

A container for utility functions that perform line-by-line reading and writing of files.

Author:

Vivek Srikumar, upadhya3

Constructor Summary

Constructors

Constructor and Description
LineIO()

Method Summary

Modifier and Type	Method and Description
static void	append(String fileName, Iterable<String> list) Append a list of strings to a file, one per line
static <T> void	append(String fileName, Iterable<T> list, ITransformer<T,String> transformer) Append a list of items to a file, one per line
static void	append(String fileName, String line) Append a string to a file
static <T> void	append(String fileName, T line, ITransformer<T,String> transformer) Append an item to a file
static InputStream	getInputStream(String fileName) This looks around to find the file, then returns an open inputstream.
static <T> ArrayList<T>	read(InputStream fileStream, String charsetName, ITransformer<String,T> transformer) This function reads an InputStream line-by-line and converts each line into an object using a transformer that is passed as a parameter.
static ArrayList<String>	read(String fileName) An implementation of read(String, Transformer<String, T>).
static <T> ArrayList<T>	read(String fileName, ITransformer<String,T> transformer) This function reads a file line-by-line and converts each line into an object using a transformer that is passed as a parameter.
static ArrayList<String>	read(String fileName, String charsetName) An implementation of read(String, Transformer<String, T>).
static <T> ArrayList<T>	read(String fileName, String charsetName, ITransformer<String,T> transformer) This function reads a file line-by-line and converts each line into an object using a transformer that is passed as a parameter.
static ArrayList<String>	readFromClasspath(String fileName) This searches for the file on the classpath before reading it.
static ArrayList<String>	readGZip(String fileName) An implementation of readGZip(String, Transformer<String, T>).
static <T> ArrayList<T>	readGZip(String fileName, ITransformer<String,T> transformer) This function reads a gzipped file line-by-line and converts each line into an object using a transformer that is passed as a parameter.
static String	slurp(String fileName) Read the contents of a file using the default charset and return as a single string
static String	slurp(String fileName, String charsetName) Read the contents of a file and return as a single string
static void	write(String fileName, Iterable<String> list) Writes a list of strings to a file, one per line.
static <T> void	write(String fileName, Iterable<T> list, ITransformer<T,String> transformer) This function writes a list of objects into a file, one per line.
static void	writeGzip(String fileName, Iterable<String> list) Writes a list of strings to a file gzipped, one per line.
static <T> void	writeGZip(String fileName, Iterable<T> list, ITransformer<T,String> transformer) This function writes a list of objects into a Gzipped file, one per line.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LineIO

public LineIO()

Method Detail

slurp

public static String slurp(String fileName,
                           String charsetName)
                    throws FileNotFoundException

Read the contents of a file and return as a single string

Throws:

FileNotFoundException

slurp

public static String slurp(String fileName)
                    throws FileNotFoundException

Read the contents of a file using the default charset and return as a single string

Throws:

FileNotFoundException

read

public static <T> ArrayList<T> read(String fileName,
                                    String charsetName,
                                    ITransformer<String,T> transformer)
                             throws FileNotFoundException

This function reads a file line-by-line and converts each line into an object using a transformer that is passed as a parameter. This passes a FileInputStream created with fileName into read(java.io.InputStream, String, ITransformer) .

Type Parameters:

T - Each line of the file represents an object of type T

Parameters:

fileName - The name of the file to be read

transformer - A transformer from String to type T

Returns:

An ArrayList containing objects of type T, with one object corresponding to each line.

Throws:

FileNotFoundException

read

public static <T> ArrayList<T> read(InputStream fileStream,
                                    String charsetName,
                                    ITransformer<String,T> transformer)
                             throws FileNotFoundException

This function reads an InputStream line-by-line and converts each line into an object using a transformer that is passed as a parameter.

Returns:

An ArrayList containing objects of type T, with one object corresponding to each line.

Throws:

FileNotFoundException

readGZip

public static <T> ArrayList<T> readGZip(String fileName,
                                        ITransformer<String,T> transformer)
                                 throws IOException

This function reads a gzipped file line-by-line and converts each line into an object using a transformer that is passed as a parameter.

Type Parameters:

T - Each line of the file represents an object of type T

Parameters:

fileName - The name of the file to be read

transformer - A transformer from String to type T

Returns:

An ArrayList containing objects of type T, with one object corresponding to each line.

Throws:

IOException

read

public static <T> ArrayList<T> read(String fileName,
                                    ITransformer<String,T> transformer)
                             throws FileNotFoundException

This function reads a file line-by-line and converts each line into an object using a transformer that is passed as a parameter.

Type Parameters:

T - Each line of the file represents an object of type T

Parameters:

fileName - The name of the file to be read

transformer - A transformer from String to type T

Returns:

An ArrayList containing objects of type T, with one object corresponding to each line.

Throws:

FileNotFoundException

read

public static ArrayList<String> read(String fileName,
                                     String charsetName)
                              throws FileNotFoundException

An implementation of read(String, Transformer<String, T>). This function reads the lines in a file and returns them.

Parameters:

fileName - The name of the file to be read

Returns:

An arraylist of the lines of the file.

Throws:

FileNotFoundException

readGZip

public static ArrayList<String> readGZip(String fileName)
                                  throws IOException

An implementation of readGZip(String, Transformer<String, T>). This function reads the lines in a gzipped file and returns them.

Parameters:

fileName - The name of the file to be read

Returns:

An arraylist of the lines of the file.

Throws:

IOException

read

@AvoidUsing(reason="Cannot be used for accessing files inside jars in the classpath",
            alternative="readFromClasspath(String fileName)")
public static ArrayList<String> read(String fileName)
                                                                                                                                                                                  throws FileNotFoundException

An implementation of read(String, Transformer<String, T>). This function reads the lines in a file and returns them.

Parameters:

fileName - The name of the file to be read

Returns:

An arraylist of the lines of the file.

Throws:

FileNotFoundException

readFromClasspath

public static ArrayList<String> readFromClasspath(String fileName)
                                           throws FileNotFoundException

This searches for the file on the classpath before reading it. If it doesn't find the file, it throws a FileNotFoundException.

Parameters:

fileName - The name of the file to be read

Returns:

An arraylist of the lines of the file.

Throws:

FileNotFoundException

getInputStream

public static InputStream getInputStream(String fileName)
                                  throws FileNotFoundException

This looks around to find the file, then returns an open inputstream. This checks the classpath first, then adds a forward slash to the file name and checks the classpath again, then it looks in the current directory. Note that this uses ClassLoader.getResourceAsStream(String), which works better in maven.

Parameters:

fileName - The name of the file to be read

Returns:

an open input stream.

Throws:

FileNotFoundException

write

public static <T> void write(String fileName,
                             Iterable<T> list,
                             ITransformer<T,String> transformer)
                      throws IOException

This function writes a list of objects into a file, one per line. Each object is transformed into a string using a transformer.

Throws:

IOException

writeGZip

public static <T> void writeGZip(String fileName,
                                 Iterable<T> list,
                                 ITransformer<T,String> transformer)
                          throws IOException

This function writes a list of objects into a Gzipped file, one per line. Each object is transformed into a string using a transformer.

Type Parameters:

T - Each line of the file represents an object of type T

Parameters:

fileName - The name of the file to be read

transformer - A transformer from String to type T

Throws:

IOException

write

public static void write(String fileName,
                         Iterable<String> list)
                  throws IOException

Writes a list of strings to a file, one per line.

Throws:

IOException

writeGzip

public static void writeGzip(String fileName,
                             Iterable<String> list)
                      throws IOException

Writes a list of strings to a file gzipped, one per line.

Throws:

IOException

append

public static <T> void append(String fileName,
                              Iterable<T> list,
                              ITransformer<T,String> transformer)
                       throws IOException

Append a list of items to a file, one per line

Throws:

IOException

append

public static void append(String fileName,
                          Iterable<String> list)
                   throws IOException

Append a list of strings to a file, one per line

Throws:

IOException

append

public static <T> void append(String fileName,
                              T line,
                              ITransformer<T,String> transformer)
                       throws IOException

Append an item to a file

Throws:

IOException

append

public static void append(String fileName,
                          String line)
                   throws IOException

Append a string to a file

Throws:

IOException